1. Field of the Invention
The present invention relates to methods of manufacturing a heat pipe integrated into the heat sink, and more particularly, to a method of manufacturing a heat pipe integrated into the heat sink produced by compression casting for avoiding the separation of the heat pipe and improving the efficiency of heat dissipation.
2. Description of the Prior Art
A CPU on the motherboard is the most important component in a computer. When the CPU is operated, a lot of heat is generated and must be quickly carried away, otherwise, the CPU will be out of order due to overheating. The conventional heat dissipating devices are commonly composed of a heat sink having a radiator fan mounted on the CPU. The heat is transmitted from the heat sink to the radiator fan and the air passing produces a cool airflow, whereby the heat is quickly and effectively dissipated due to forced convection by a fan.
The heat sink mounted on the CPU is composed of metal with high conductivity but the dissipating efficiency is limited, and is especially insufficient for notebooks. Therefore, a heat pipe is filled with heat conductive liquid and is mounted on the heat sink to carry away the heat more quickly and effectively.
The conventional heat sink with pipes, as shown in FIG. 5 and FIG. 6, has a groove (a1) for accommodating heat pipe (b) on the heat sink (a). The heat pipe (b) is curved to the same arc of the groove (a1) and then fitted onto the groove (a1) with heat conductive adhesive (c). The heat pipe (b) has been filled with heat conductive liquid in advance.
Yet the heat conductive adhesive (c) for fixing the heat pipe (b) into the groove (a1) of the heat sink (a) forms a layer of another substance between heat pipe (b) and the heat sink (a) so that the heat-radiating rate is decreased and the efficiency of heat dissipation is also reduced.
Once the heat conductive adhesive (c) absorbs heat, it easily hardens and causes the separation of the heat pipe (b). The heat pipe (b) cannot be in contact with the heat sink (a) very closely and the heat-radiating rate is lower. By the way, due to the use of heat conductive adhesive (c), difficulties in assembling the heat sink and cost of the production are increased.
Furthermore, only half of the circumference of the section of the heat pipe (b) is connected to the heat sink (a) thus the contact area between the heat pipe (b) and the heat sink (a) is only half of the total surface area of the heat pipe (b). Since the contact area for heat-dissipating is decreased, the efficiency of heat dissipation is also reduced.
In addition, when the heat pipe (b) is shaped and bent with the same curve of the groove (a1) of the heat sink (a), the tolerance is difficult to avoid when being assembled. Thus, the heat pipe (b) cannot contact the groove (a1) of heat sink (a) very closely. This further increases the difficulty of assembling the heat sink. Also, the bending point of the heat pipe (b) has a stress concentrated phenomenon and tends to break when the heat conductive liquid inside the heat pipe (b) absorbs heat and expands. The leakage of the heat conductive liquid will also reduce the efficiency of heat dissipation.